The present invention relates to a multi-layer type lock core structure of a cylindrical lock, having multi-layer and multi-pin design which provides numerous possibility of change and enhances the safety of the lock. Therefore, the lock can be more widely applied to various fields. In case the key misses or is duplicated, the safety of the lock can be still ensured. In addition, the lock core has no force application point so that the lock is prevented from being pried and damaged by an alien tool.
A conventional cylindrical lock has a lock casing in which a lock core, a lock seat and seven sets of number-changing engaging pins are installed. The end of the key is formed with multiple dents with different depths for pressing and pushing the engaging pins and retracting the engaging pins into the dents so as to disengage the lock core from the lock seat and turn and unlock the lock. The above seven pin-type cylindrical lock has small volume and can be conveniently used so that it is widely applied to specific appliances such as vending machine and electric game. However, it often takes place that such lock is damaged by a specific tool. Moreover, such seven pin-type cylindrical lock can be unlocked by single key. Therefore, in case the key misses or is duplicated by unauthorized person, the lock will lose its function and needs to be replaced. This leads to waste of labor and money.
In addition, as shown in FIG. 4, the rims of the key way and the lock core of the conventional cylindrical lock are formed with lock core guide channel 1a for guiding a tenon 3a of the key during insertion. The guide channel 1a often serves as a force application point for an alien tool to insert and pry open the lock.
It is therefore a primary object of the present invention to provide an improved multi-layer type lock core structure of a cylindrical lock, having multi-layer and multi-pin design. There are twelve sets of upper pins and ten sets of lower pins which provides over twelve sets of possibility of change in changing the number so that in case the key misses or is duplicated, the safety of the lock can be still ensured. The number can be more variously changed to avoid cost for replacement of the lock and repeatedly use of the lock. Therefore, the lock can be more widely applied to various fields.
It is a further object of the present invention to provide the above cylindrical lock in which the conventional key guiding channel formed on the rims of the key way and the lock core are eliminated and the lock way has a complete design. Therefore, there is no force application point for an alien tool such as a conventional cylindrical key or universal key to insert and pry open the lock. Moreover, the internal pin ring fixing spile of the lock has cylindrical shape and polished surface. Therefore, even if a tool is inserted, the tool can hardly press and forcedly rotate the lock core. Even if the tool can turn the fixing spile, the twelve engaging pin design possesses better strength than the connecting pin of the fixing spile so that the connecting pin of the fixing spile will drive the pin ring to idle so that the lock cannot be rotated and unlocked. Therefore, the lock is more resistant against damage and can provide enhanced safety.
The present invention can be best understood through the following description and accompanying drawings wherein: